They were horrified when they saw the photo?
Bollocks.
Politicians shouldn't be attending partisan rallies, where there is such open incitement to violence against their constituents.
However, if they are misguided enough to attend and stupid enough to be photographed there, the very least they could do is to check what else was in the shot. Otherwise - it just looks like they support this hateful shite, doesn't it?
Are they really that breathtakingly stupid and naive?